I am setting up the project for my Programme Management team. We deal with Projects. So instead of Story and Task, I am thinking of introducing custom issue type called Project. I might consider including one more called "Operational Activity". Are there any disadvantages in not using the standard issue types like Story and Task ? Would plugins support such custom issue types? Is there any benefit of using Story and Task over custom issue types? We intend to use Portfolio for Jira tool. We would have Epics and Initiative as a level higher than Epics. Would Portfolio work fine with custom issue types?